Let's learn something today. See US patent 6005950
Dave this works better (Thanks Gyraf)
It gives you PDF's although one page at a time.
If you have real Acrobat, open page one and keep adding pages behind page one! Then save the multi page file.
General link: Hint Put US before the patent #
i.e. US6005950 in the "View Patent Application" box to search for any US patent.
http://gb.espacenet.com/espacenet/gb/en/e_net.htm
Exact link:
US6005950
Think like this a "passive DI box backwards".
Take a look at figure 5.
Lets follow it.
XLR connector to a ballanced H pad PAD assume 40dB for now.
Parts 77 and 76-6 form a high freq. roll off. (to simulate a guitar speaker roll off above 5Khz).
DI Transformer wired backwards.
If you assume a high quality DI transformer like the Lundahl
L1530
Wire it as a 1:7 stepup with High Z going to the guitar amp through the output pot. Warning any transformer may need the termination resistor to get best square wave response. Since you need to throw away levels in this application the connection of 1:3.5 may work better for this transformer.
I assumed +4dBm -40dB pad +16dB for transformer should give you
86mV across the pot. This should give you plenty of signal for the guitar amp.
Just plain simple.
